The proposed research will explore the properties of central nervous pathways that are involved in the control of gaze. The emphasis in all experiments will be upon premotor neurons that project to extraocular or spinal motor nuclei. By focusing on this group of neurons we hope to obtain information about how signals from integrative gaze control systems within the brain stem are transmitted to motoneurons involved in eye and head movements. In three experiments we will stimulate structures such as the pontomedullary reticular formation, the vestibular nuclei and the interstitial nucleus of Cajal which contain premotor neurons while recording the response of somatic and extraocular motoneurons. These experiments should provide an indication of the locations of premotor neurons and their action on various types of motoneurons - data which is a prerequisite to understanding the function of gaze control systems. In another three experiments we will record the activity of premotor neurons in the reticular formation during shifts in gaze triggered by pattered electrical stimulation of the superior colliculus and semicircular canal nerves. Stimulus patterns will be designed to mimic effects produced by natural visual or vestibular stimuli. These experiments will allow us to utilize many powerful electrophysiological techniques to analyze the neural activity that accompanies shifts of gaze. A final experiment will use similar techniques to explore the connections of neurons in the interstitial nucleus of Cajal, an important center for vertical eye movements. Results of the seven experiments should provide information about the inputs received by and the projections of premotor neurons and about the role of such neurons in eye and head movements that accompany shifts in gaze. Knowledge of the properties of this identified group of neurons should be an important step toward understanding the integrative circuitry that controls the direction of gaze.